Chinese scientists have used a specially developed chemical formula in conjunction with an electrical charge to make fingerprints glow, allowing observers to distinguish a much higher level of detail than was previously possible. The technique, detailed in a paper published in the journal Angewandte Chemie last month, could aid forensic investigators in matching partial or smudged fingerprints to suspects, as well as stimulating the development of more accurate and reliable biometric security systems.
Developed by researchers at Zhejiang University in Hangzhou, the method takes advantage of a phenomenon known as electrochemiluminescence, in which application of an electrical charge causes a chemical formula to enter an "excited state," with the formula returning to its ordinary state by expelling the surplus energy as light. In this case, the fingerprint is first transferred to a metallic plate serving as an electrode, before being coated in the chemical solution. The fatty deposits that make up the print repel the solution, so when an electrical current is applied it shows up as a highly detailed negative.
Crucially, the resulting image is well-suited to being captured by CCD camera sensors, potentially making it much simpler for governments, police, and other law enforcement agencies to keep high-resolution digital fingerprint archives.